Transmitter



Oct. 8, 1940. l. E. MOUROMTSEFF ET m. 2,217,447

TRANSMITTER Filed July 9. 1938 2 Sheets-Sheet 1 J A 1 J WITNESSES: 4 4 INVENTORS C? [/10 [Mauromtse/f anaYeoyefini/yore.

8, 0- I. E. MOUROMTSEFF ET AL 2,217,447

TRANSMITTER Filed July 9, 1938 2 Sheets-Sheet 2 WITNESSES: INVENTORS [00E Mouramfse/ and Georyefi Af/y-ore.

ATTORNEY Patented Oct. 8,1940

UNITED STATES PATENT OFFICE TRANSMITTER vania Application July 9, 1938, Serial No. 218,310

17 Claims.

Our invention relates to generators for electrical oscillations and particularly to such generators in which a magnetic field is employed to traverse the electron path between the anode and the cathode.

One object of our invention is to provide an electrical generator of the above-mentioned type which is particularly adapted to generate ultra high frequency currents.

Another object of our invention is to provide a generator of the type described above in which the electrical circuit elements are symmetrically disposed relative to the tube axes.

Another object of our invention is to provide an electric generator which has a naturalfrequency, or plurality of frequencies, of electrical vibration; in other words, the generator has a plate structure which constitutes in itself an oscillatory circuit having uniformly distributed inductance and capacity which fixes the generated frequency.

Still another object of our invention is to provide an electrical discharge tube in which the output can be varied by varying a magnetic field traversing the electron paths between the anode and cathode thereof.

Still another object of our invention is to provide an electrical generator, the output of which can be varied at will and in substantially instantaneous response to the fluctuations of a controlling magnetic field, or of the anode potential.

Other objects of our invention will become apparent upon reading the following description in which:

Figure 1 is a view partly in cross section and partly in elevation of a tube embodying the principles of our invention, together with schematically diagrammed electrical circuits for using the same.

Fig. 2 is a cross sectional view taken on the line II-II of Fig. 1.

Fig. 3 is a diagram used. in explaining the principles of our invention.

Fig. 4 is a view of the same type as Fig. 1 of a modified form of our invention;

Fig. 5 is a view of a portion of the tube of Fig. 1 arranged with a modified form of antenna connection; and

Fig. 6 is a detailed view, partly in cross-section, of a tuning means employed in the tube of Fig. 1.

Referring particularly to Figure 1, a vacuumtight enclosure I which may be of glass, quartz or other suitable material, and which is preferably made in the form of an elongated cylinder, has reentrant stems 2, 3 at its respective ends through which are sealed in-leading wires which support electron emissive cathodes 4, 5 which may suitably be of the thermionically emissive type. A cylindrical metallic electrode 6 may be supported by an in-leading wire 1 and is prefer- 5 ably made coaxial with the enclosure I. The two cathodes 4 and 5 may be made to project by approximately equal distances which may be comparatively short inwardly from each end of the cylinder 6. Also extending inward from each end of the cylinder 6 is a pair of diametrically opposite slots 8, 9, l0, II. The slots 8, 9, II], II preferably extend equal distances inward from their respective ends of the cylinder 6, and may extend so far as to leave only a narrow connecting bridge 12 at substantially the midpoint of the latter. The supporting in-lead I is likewise attached to the cylinder 6, preferably at its midpoint. At two points which are preferably spaced equally distant from the midpoint of the cylinder 6, connecting leads l3, M are sealed through the enclosure I, and extensions of these leads form a transmission line for .conveying the output of tube l to any load circuit such as a single antenna or a pair of antennae I5, I6 which are preferably each of the same length as the cylinder 6. Alternatively, however, either antenna IE or IE may be N times the length of the electrode 6 where N is any integer. We prefer to provide means such as the two solenoids ll, 30 I8 for producing a magnetic field parallel to the axis of the anode cylinder 6. We may provide means at l9 and 20 by which the magnetic field in the region of each cathode 4 may be adjusted.

The source of current 2i which energizes the magnets l1 and I8 should be of the continuous (i. e., direct) current type.

To energize the two cathodes 4 and 5, we provide a pair of circuits 22, 23 which are preferably provided with tuning means such as the reflecting bridges 24 and 25 for imparting to that portion of either of them which is traversed by highfrequency currents an electrical length which is approximately equal to that of cylinder 6. One suitable arrangement for so tuning the circuits 22, 23 is to make the leads adjacent the seals at each end of the container l in the form of a concentric transmission line shown in detail in Fig. 6; that is to say, in the form of a tube 21 with a conducting core 28 in its axis, and to provide this tube with a telescoping end portion 24 which slides upon the core 28 and is insulated from tube 21 by an insulating film and which may be moved in and out so as to make the electrical length intervening between the respective filament 4 or and the outer end of said tube apthe length of cylinder 6.

proximately one-half the wave length pointed out below as characterizing the electrical vibration of anode cylinder 6. To supply operating energy producing current flow between the cylinder-.6 and the twocathodes 4 and 5, we connect an electrical source of current 26 between the leads 1 and thetwo telescoping ends, or other half wave points, on the respective input circuits supplying current to the cathodes 4 and 5. We may provide a variable impedance 2! so that the output of source 26 may be controlled. The source 26 should be of the continuous (i. e., direct) current type with its positive terminal connected to the lead 1. As a particularly convenient and desirable arrangement, we, may connect the negative lead from the source 26 to ground and may also ground the telescoping collars or other half-wave points on the above described circuits which supply current to the cathodes 4 and 5.

The reference numerals in Fig. 2 apply to the same structural elements as do the similar reference numerals in Fig. 1, and Fig. 2 is accordingly believed to require no separate explanation.

Upon energizing the sources 2| and 26 and bringing the cathodes 4 and 5 up to incandescence, it will be found that the above described system will generate electrical oscillations having a wave length equal to approximately twice In other words, the electrical potential distributions of the cylinder 6 will be as indicated symbolically in Fig. 3 where the dotted curve represents one instantaneous value of electrical potential varying from point to point along the length of cylinder 6, the axis of said cylinder constituting the zero for ordinates of the curve. Since the length of cylinder 6 may obviously be made relatively small the apparatus which we have described is capable of generating electrical oscillations of relatively short wave length.

While we have shown the leads I 3, l4 as connected to two separate antennae, it will be recognized that the latter are merely symbolical of any form of tunable electrical systems adapted to respond to oscillations of a wave length equal to twice the length of the cylinder 6.

It willbe noted that theabove. described arrangement provides a very simple, rugged and inexpensive arrangement for generating ultra high frequency electrical vibrations, and for modulating them at will, and that it is symmetrical relative to the midpoint of the enclo-' sure I and is adapted by arrangement in a horizontal position to be made symmetrical relative to the earth and its surroundings.

As a specific illustration of one embodiment of our invention, the tube l in Fig. 1 may be of glass 1 inches in diameter and 4 inches in overall length. The cathodes 4 and 5 may each.

consist of tungsten wire .005 inch in diameter and /2 inch in length between the ends of the heated portion. The tube I should be evacuated to the highest vacuum which is practicable, and under these conditions, the cathodes 4, 5 will require approximately 3 amperes at 1.5 volts to 5 raise them to a proper operating temperature.-

The cylindrical anode 6 may have an overall length of 1 /2 inches and be inch in outside diameter and .2 inch in inside diameter. The slot 8 may be '1 inch wide and the bridge-portion I2 may be inch in length in an axial direction. The concentric transmission lines for carrying a heating current to the cathodes 4 and 5 may each comprise a cylinder of copper tubing approximately 8 inches long and having a wall 3% inch thick, together with a central core of copper wire about 3 inch in diameter. The magnetizing windings l1 and I6 may consist of approximately 11000 turns of insulated copper wire of #24 enameled copper, and the source 2l should be of such size that it can supply a current of .25 ampere to each said winding. The source 26 should be able to supply .020 ampere at 1500 volts to operate the tube.

bodying our invention which differs from Fig. 1 in that its'cathode consists of a single filament 3| extending along the axis of the anode cylinder 6 from one end of the latter to the other. The separate sources of heating current 22 and 23 of Fig. 1 are accordingly replaced by a single source 32 which may conveniently be the secondary of a transformer connected to an alternating-current source. With this arrangement, there is, of course, no occasion for the employ- 'l0 Fig. 4 shows a modification of the tube emment of the tuning bridges 24, 25. The negative terminal of the direct-current source 26 and its associated resistor 21 are then connected to the midpoint of the transformer secondary 32. If desired, said midpoint may be connected to ground.

f Since otherwise the circuit connections and structure of the tube of Fig. 4 are similar to those 'of Fig. 1, the remaining structural elements need no separate description, butv are designated by the same reference numerals as corresponding elements in Fig. 1.

In Fig. 5 is shown a modified way of connecting the antennae or output circuit for the tubes of either Fig. 1 or Fig. 4. The respective antennae 33"ai1'd 34, each equal in length to anode cylinder 6, are connected to two points on opposite sides of the slot l0 (or 8) in anode 6, said points preferably being each distant from the midpoint of anode 6 by a distance adjusted in operation in accordance with well-known prac tice in the radio and telephone arts so as to 'match' the load impedance to the tube impedance. The leads 35 and 36 form a transmission line to convey the output from anode 6 to an- -tennae 33 and 34.

While we have described a particular embodiment of our invention, the principles thereof are capable of broad application which will be obvious to those skilled in the art. We accordingly desire that the following claims .shall be given the broadest construction by which their terms are susceptible of limitations made necessary by the prior art.

. We claim as our invention:

1. In combination, a vacuum-tight enclosure, a pair of electron sources displaced from each other therein, means to produce a magnetic field along the line connecting said electron sources, a cooperating electrode comprising two hemi-cylinders having their axes substantially coincident withsaid line, at least one antenna having a length which is N times the length of said cooperating electrode connected to the latter, where N is any integer, a. source of electric power connected to substantially the midpoint of said cooperating electrode, a power supply having leads for each said electron source and means to tune a portion of the leads therefrom to a wave-length which is twice the length of said cooperatingelectrode, and means to connect said source to two points on said leads which are electrically distant I 2. In combination, a vacuum-tight enclosure, a pair of electron sources displaced from each other therein, means to produce a magnetic field along the line connecting said sources, a cooperating electrode comprising two hemi-cylinders having their 'axes substantially coincident with said line, a source of electric power connected to substantially the midpoint of said cooperating electrode, a power supply for each said cooperating electrode, a power supply having leads for each said electron source and means to tune a portion of the leads therefrom to a wave length which is twice the length of said cooperating electrode, and means to connect said source to two points on said leads which are electrically distant from their associated electron sources by the length of said cooperating electrode.

3. In combination, a vacuum-tight enclosure, 9. pair of electron-sources displaced from each other therein, means to produce a magnetic field along the line connecting said sources, a cooperating electrode comprising two hemi-cylinders having their axes substantially coincident with said line, at least one antenna having a length which is N times the length of said cooperating electrode, where N is any integer, connected to the latter respectively -at two points equidistant from its midpoint, a source of electric power connected to substantially the midpoint of said cooperating electrode, a power supply having leads for each said electron source and means to tune a portion of the leads therefrom to a wave length which is twice the length of said cooperating electrode, and means to connect said source to two points on said leads which are electrically distant from their associated electron sources by the length of said cooperating electrode.

4. -In combination, a vacuum-tight enclosure, a pair of electron sources displaced from each other therein, means to produce a magnetic field along the line connecting said sources, a cooperating electrode comprising two hemi-cylinders having their axes substantially coincident with said line, a source of electric power connected to substantially the midpoint of said cooperating electrode, a power supply having leads for each said electron source and means to tune a portion of the leads therefrom to a wave length which equals twice the length of said cooperating electrode, and means to connect said source to two points on said leads which are electrically distant from their associated electron sources by the length of said cooperating electrode.

5. In combination, a vacuum-tight enclosure, a pair of electron sources displaced from each other therein, means to produce a magnetic field along the line connecting said sources, a cooperating electrode comprising two hemi-cylinders having their axes substantially coincident with said line, two antennae having lengths which are N times the length of said cooperating electrode, where N is any integer, connected to the latter respectively at two points equidistant from its midpoint, a source of electric power connected to substantially the midpoint of said cooperating electrode, a power supply having leads for each said electron source and means to tune a portion of the leads therefrom to a wave length which is twice the length of said cooperating electrode, and means to connect said source totwo points on said leads which are electrically distant from their associated electron sources by the length of said cooperating electrode.

6. In combination, a vacuum-tight enclosure, a pair of electron-sources displaced from each other therein, means to produce a magnetic field along the line connecting said sources, a cooperating electrode comprising two hemi-cylinders having their axes substantially coincident with said line,a source of electric power connected to substantially the midpoint of .said cooperating electrode, a power supply having leads for each said electron source and means to tune a portion of the leads therefrom to a wave length which is twice the length of said cooperating electrode, and means to connect said source to two points on said leads which are electrically distant from their associated electron sources by the length of said cooperating electrode.

'7. In combination, a vacuum-tight enclosure, a pair of electron-sources displaced from each other therein, means to produce a magnetic field along the line connecting said sources, a cooperating electrode comprising two hemi-cylinders having their axes substantially coincident with said line, at least one antenna having a length which is N times the length of said cooperating electrode connected to the latter, a direct current source of power connected to substantially the midpoint of said cooperating electrode; a power supply having leads for each said electron source and means to tune a portion of the leads therefrom to a wave length which is twice the length of said cooperating electrode, and means to connect said source to two points on said leads which are electrically distant from their associated electron sources b the length of said cooperating electrode.

8. -In combination, a vacuum-tight .enclosure, a pair of electron sources displaced from each other therein, means to produce a magnetic field along the line connecting said sources, a cooperating electrode comprising two hemi-cylinders having their axes substantially coincident with said line, a direct current source of power connected to substantially the midpoint of said cooperating electrode, a power supply having leads for each said electron source and means to tune a portion of the leads therefrom to a wave length which is twice the length of said cooperating electrode, and means to connect said source to two points on said leads which are electrically distant from their associated electron sources by the length of said cooperating electrode.

9. In combination, a vacuum-tight enclosure, a pair of electron sources displaced from each other therein, means to produce a magnetic field along the line connecting said sources, a cooperating electrode comprising two hemi-cylinders having their axes substantially coincident with said line, at least one antenna having a length which is N times the length of said cooperating electrode, where N is any integer, connected to the latter, a direct current source of power connected to substantially the midpoint of said cooperating electrode, a power supply having leads for each said electron source and means to tune a portion of the leads therefrom to a wave length which is twice the length of said cooperating electrode, and means to connect said source to two points on said leads which are electrically distant from their associated electron sources by the length of said cooperating electrode.

I 10. In combination, a vacuum-tight enclosure, a pair of electron-sources displaced from each other therein, means to produce a magnetic field along the line connecting said sources, a cooperating electrode comprising two hemi-cylinders having their axes substantially coincident with said line, a direct current source of power connected to substantially themidpoint of said cooperating electrode, a power'supply having leads.

for each said electron source and means to tune a portion of the leads therefrom to a wave length which is twice the length of said cooperating electrode, and means to connect said source to twopoints on said leads which are electrically distant from their associated electron sources by the length of said cooperating electrode.

' 11. In combination, a vacuum-tight enclosure, a pair of electron sources displaced from each other therein, means to produce a magnetic field along the line connecting said sources, a cooperating electrode in the form of a cylinder the axis of which coincides with said line and which has 'a pair of diametrically opposite slits ex-' tending toward its midpoint from each of its ends, at least one antenna having a length which is N times the length of said cooperating electrode, where N is any integer,- connected to the latter, a source of electric power connected to substantially the midpoint of said cooperating electrode, a power supply having-leads for each 'saidelectron source and means to tune a portion of the leads therefrom to a wave length which is twice the length of said cooperating electrode, and means to connect said source to two points on said leads which are'electrically distant from their associated electron sources by the length of said cooperating electrode.

12. In combination, a vacuum-tight enclosure, a pair of electron sources displaced from each other therein, means to produce a magnetic field foo leads therefrom to a wave length which is twice the length of said cooperating electrode, and

means to connect said source to two points on said leads which are electrically distant from their associated electron sources by the length of said cooperating electrode.

13. In combination, a vacuum-tight enclosure.

a pair of electron sources displaced from each other therein,means to produce a magnetic field along the line connecting said sources, a cooper ating electrode in the form of a cylinder the axis of which coincides with said line and which has a pair of diametrica'llyopposite slits extending toward its midpoint from each of its ends, at least one antenna'having a length which is N times the length ofsaid cooperating electrode connected, where N is any integer, to the latter at points equidistant from its midpoint, a source of electric power connected to substantially the midpoint of said cooperating electrode, a power supply having leads for each said electron source and means to tune a portion of the leads therefrom to a wave length which is twice the length of said cooperating electrode, and means to connect said source to two points on said leads which are electrically distant from their associated electron sources by the length of said cooperating electrode.

14. In combination, a vacuum-tight enclosure, a pair of electronsources displaced from each other therein, meansto produce a magnetic field along the line connecting said sources, a cooperating electrode in the form of acylinder the axisof which coincides with'said line and which has a pair of diametrically opposite slits extending toward its midpoint from each of its ends, a source of electric power connected to substantially the midpoint of said cooperating electrode, a power supply for each said electron source supplying the latter through a concentric-type transmission line comprising a concentric rod and cylinder having tuning means comprising a reflecting bridge, and means to connect said source to each of said reflecting bridges.

15. In combination, a vacuum-tight enclosure, a pair of electron sources displaced from each other therein, means to produce a magnetic field along the line connecting said sources, a cooper.- ating electrode in the form of a cylinder the axis of which coincides with said line and which has a pair of diametrically opposite slits extending toward its midpoint from each of its ends,

two antennae having wave lengths which are of the length of said cooperating electrode and which are connected to the latter respectively at two points equally distant from its midpoint, a

source of electric power connected to substantially the midpoint of said cooperating electrode,

, a power supply for each said electron sourcesupplying the latter through a concentric-type transmission' line comprising a concentric rod and cylinder having tuning means comprising a reflecting bridge, and means to connect said source to each of said reflecting bridges.

16. The arrangement specified in claim 14 but having the terminal of said source which is nearest to said cathodes grounded.

17; The arrangement specified in claim 15 but having the terminal of said source which is nearest to said cathodes grounded.

ILIA E. MOUROMTSEFF.

GEORGE R. KILGORE. 

